Initiator and cap



Aug, 3, 1943. LE ROY v. CLARK INITIATOR AND CAP Filed March 20, 1940 I vdwo m IIII CI INVENT OR.

Z [1?0) V. CA?

ATTORNEY;

?atentecl Aug, 3,-351943 attain arcane rurrra'rca turn car he lRoy W. (Clark, lLatrohe, lia, assigncr to American l'lyanamid and Chemical @orporation, New York, N. 1., a corporation of Delaware Application March. Zll, 1944?, Serial N0. 324,996

ll (Claims.

The present invention relates to the use of heavy metal salts of nitroaminoguanidine and particularly those'of lead, copper and barium, listed in the order of their preference, as an ignition, an initiator or primary charge, or as an ingredient thereof.

It is common practice to use in ammunition and blasting caps a primer, ignition, or initiatcharge as diazodinitrophenol, mercury-fulrninate or lead azide or a composition including one or more of these substances. The primary ohiect of the present invention is to replace in whole or in part such substance with a heavy metal salt of nitroaminoguanidine because of its ease of handling, simplicity of manufacturing, cheaper cost and the fact that. the physical nature thereof makes it more desirable for this primer of the center fire type; and \v Fig. 8 is a similar view of ammunition of the rim fire type.

El heavy metal salt of nitroaminoguanidine he prepared as follows:

.65 grains of hydrazine sulfate is dissolved in cc. of ammonium hydroxide solution (1 N). grams of nitroguanidine is added over a od of approximately minutes with mild agitation. The mixture is stirred at C. for the hour and then at 65 C. for an additional hour and finally vacuum concentrated to 600 cc.

4 L-pon cooling to 15 (3., crystals of nitroaminoguanldine are precipitated.

To a quantity of nitroaminoguanidine in water Any heavy metal salt of nitroaminoguanidine may he thus prepared, although those'of lead, copper and barium are preferred in the order listed because of their greater suitability for the use specified.

Referring now to the drawing,

lg. 1 shows an electric blasting cap including the usual cylindrical metal casing i containing the secondary or base charge ii of any well known composition and with or without a primary initiating charge 3 comprising a heavy metal salt of nitroarninoguanidine either alone or in admixture. The plug it, of suitable insulating material through which the electric lead wires 5 pass, is provided with a depression into which is amxed an ignition charge t which includes a heavy metal salt of nitroaminoguanidine either alone or in admixture. A. fine ignition wire extends between the ends of the lead wires 5 and is embedded in the initiator charge.

Above the plug it is a suitable waterproof composition l and a seal of sulfur or the like 23 as is usual for the purpose of embedding the lead in wires, retaining the various compositions within the casing and preventing the leakage of mole ture thereinto.

Fig. 2 is similar in construction to that of Fig. 1 except that the ignition charge is in the form of a match head carried by the end or" the lead in wires 5.

' In Fig. 3, a similar construction is shown but in this modification the primary initiating charge is a loose fill between the secondary or base charge 2 and the plug l. in this incurfication the lower portion of charge ll adjacent to the top of charge 2 may be subjected to pressure.

Fig. l illustrates a delay electric blasting cap in which a delay element ill of the usual type containing a delay composition ii is superimposed upon the primary initiating charge which is in turn superimposed upon the secondary or base charge 2. inthis case, the-ignition charge t, while shown in the term illustrated in Fig. l, obviously may be either that of Fig. 2 or Fig. 3.

Hg. 5 shows a cap oi the fuse type in which a flexible fuse i2 is crirnped into the casing 51 and in contact with a primary initiating charge which consists of a heavy metal salt of nitroaminoguanidlne either alone or in admixture, and which is superimposed upon a secondary or case charge 2.

In Fig. 6 a similar construction is shown but in this modification, the ignition charge it, which may comprise a heavy metal salt olnitroaminoguanidine either alone or in admixture, and a reenforcing insert or capsule it having an aperture it, have been placed between the end of the fuse i2 and the primary initiating charge Fig. '7' illustrates an igniter or primer cap for center fire ammunition. Here, a short casing I6 is provided with a primer composition I! including a heavy metal salt of nitroaminoguanidine held between the top of the casing and an anvil I8. When such a cap is incorporated in the ammunition shell, the firing pin of the weapon causes the primer charge to flre by pinching it between the casing and the anvil and so ignites the propellant charge in the ammunition shell in the usual manner.

In Fig. 8, the primer composition of the present invention is shown at l9 and located between the folded periphery of casing 20 in rim fire ammunition. In this case, the firing pin of the weapon fires the primer composition by pinching it between the folded rim of the shell itself, thus igniting the propellant charge 2| as usual.

In all of the above cases, it is understood that the initiator, ignition or primary charge shall include a heavy metal salt of nitroaminoguanidine, those of lead, copper andv barium being preferred in the order listed. Mixtures of these compositions may be used. Such a composition may be used for any purpose for which mercury fulminate or any other primary detonant is useful.

In the claims, where the initiator charge is referred to, it is intended to include also an ignition and/or primary charge as above described, as these types of charges are considered to be the equivalent for patent purposes.

While the invention has been shown and described with particular reference to specific embodiments, it is to be understood that it is not to be limited thereto but is to be construed broadly and restricted solely by the scope of the appended claims.

I claim:

1. An initiator charge for 'detonating purposes including a heavy metal salt of nitroaminoguanidine.

2. An initiator charge for detonating purposes including lead nitroaminoguanidine.

3. An initiator charge for detonating purposes including copper nitroaminoguanidine.

4. An initiator charge for detonating purpose including barium nitroaminoguanidine.

LE ROY V. CLARK. 

